The Sandia Z Machine was used to develop a new shock-wave technique to measure an important material property. Image courtesy Randy Montoya. For a larger version of this image please go here.

Violent collisions between the growing Earth and other objects in the solar system generated significant amounts of iron vapor, according to a new study by LLNL scientist Richard Kraus and colleagues.

The results show that iron vaporizes easily during impact events, which forces planetary scientists to change how they think about the growth of planets and evolution of our solar system.

For planetary scientists, one of the most important and complex research areas is predicting how planets form and evolve to their current state.

Generally speaking, planets form by a series of impacts, with the speed of the impacts being slow at first, a few miles per hour, but then faster as the planets grow larger, up to 100,000 miles per hour.

At the end stages of formation, when the impact speeds are high and the material conditions are extreme (high temperatures and pressures), planetary scientists don't have great models for how to describe what happens to the colliding bodies.

"One major problem is how we model iron during impact events, as it is a major component of planets and its behavior is critical to how we understand planet formation," Kraus said.

"In particular, it is the fraction of that iron that is vaporized on impact that is not well understood."

Using Sandia National Laboratory's Z-Machine, the team developed a new shock-wave technique to measure an important material property -- the entropy gain during shock compression. By measuring the entropy, they determined the critical impact conditions to vaporize the iron within objects that collide with the growing Earth.

The scientists found that iron will vaporize at significantly lower impact speeds than previously thought. This translates to more iron being vaporized during Earth's period of formation.

"This causes a shift in how we think about processes like the formation of Earth's iron core," Kraus said.

"Rather than the iron in the colliding objects sinking down directly to the Earth's growing core, the iron is vaporized and spread over the surface within a vapor plume. After cooling, the vapor would have condensed into an iron rain that mixed into the Earth's still-molten mantle.

"The timing of Earth's core formation can only be determined via chemical signatures in Earth's mantle, a technique that requires assumptions about how well the iron is mixed. This new information actually changes our estimates for the timing of when Earth's core was formed," Kraus added.

Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

Felling of tropical trees has soared, satellite shows, not slowedWashington DC (SPX) Feb 26, 2015
The rate at which tropical forests were cut, burned or otherwise lost from the 1990s through the 2000s accelerated by 62 percent, according to a new study which dramatically reverses a previous estimate of a 25 percent slowdown over the same period.
That previous estimate, from the U.N.'s Food and Agriculture Organization's (FAO) Forest Resource Assessment, was based on a collection of rep ... read more

The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes.
AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties.
Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement
All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.